A major research area in sports rackets employing strings to bounce the ball is about string and frame vibration caused by the impact of the ball on the string network. Upon the impact, the string network will vibrate, mostly in up and down harmonic motions with gradually diminishing amplitude perpendicular to the plane of the string network. The motion of the strings will propagate to the frame to which the ends of the strings are attached. Then the frame will begin its own in-plane and out-of-plane vibration modes executed along with the strings' vibration until the energy is spent by internal molecular friction.
There have had many prior arts with arrangements to reduce the string vibration. For example, the ends of some strings, near the throat or frame, may be anchored through a cushion device installed inside a throat member or frame to absorb shock caused by the affected strings' sudden tightening. Or, a damping device, commonly in the form of elastic buttons, attached onto a string to drag the string against up-and-down vibratory motion. However, there has been no invention which could have all the strings in a sports racket cushioned against vibration. The difficulty for an effective improvement like that lies in weight consideration of a racket since good performance depends on having its weight optimally reduced and controlled. The present invention is able to cushion all strings in a racket against up-and-down vibratory motion with minimum weight penalty and accomplishes this in an ingenious way by taking advantage of a special frame structure herein the frame is primarily designed for minimum weight and provides for the addition of damping devices applied to the frame to damp all strings thus requiring no additional structural arrangement.